1. Field of Invention
This invention relates to a system for correcting an image projected on a surface that is at an oblique angle to a line of projection. The system corrects the displayed image by manual or automatic adjustment of a LCD panel or a mirror angle.
2. Description of Related Art
In general, a domestic projector is used for projecting an image received from a TV or a VCR on a wall or on a separately provided screen for displaying the image.
As shown in FIG. 1, the projector includes a light source 1a for generating light, a focusing lens 1b for focusing the light received from the light source 1a, and a first polarizing plate 1c for polarizing the light passed through the focusing lens 1b. A display element of a liquid crystal display (LCD) panel 1d is composed of pixels arranged in matrix form that are irradiated by the light passing through the polarizing plate 1c. A second polarizing plate 1e polarizes the light of the image displayed on the LCD panel 1d according to video signals received from an external source. A focusing lens 1f is movably mounted for adjusting the distance of the focusing lens to the LCD panel 1d, thereby projecting the video image of to the LCD panel 1d, on an external screen.
However, as shown in FIG. 2, the line of projection may be at an angle .alpha. to a wall adjacent a bright window. This line of projection may be necessary due to obstacles in a room or to insufficient space available in a room.
As is commonly known, the image projected on a screen, or a wall surface, at an angle other than a right angle to the screen is distorted. A screen at an oblique angle to the line of projection is referred to as a sloped screen.
Therefore, as shown in FIG. 2, the size of the image projected on the screen of FIG. 1 at an angle sloped to the screen is displayed differently than an original image.
Conventionally, in order to correct the distortion of the image, a user could manually adjust the position of the projector itself to face the screen surface at a ninety degree angle, which may be inconvenient.